Mouthpiece



Nov. 13, 1934. H. P. ROBERTS MOUTHPIECE Original Filed April 19 INVENTOR. ff. PRO 6 erzs,

TORNEY Patented Nov. 13, 1934 UNITED PATENT OFFICE MOUTHPIECE Claims.-

This invention relates to sound collectors, and more particularly to mouthpieces for dictating machines.

An object of this invention is to provide a mouthpiece of sound collector which is large enough to collect a major portion of the sounds emitted by the speaker or dictator while the mouthpiece is sufficiently far removed from the speakers face to receive both the guttural and nasal sounds, and yet one which will not be excessively heavy. 7

Another object is to provide a mouthpiece or sound-collector which tends to eliminate or absorb exceptionally loud or intense sounds, and yet collect and concentrate without materially modifying sounds within the usual or predetermined range of intensity.

A further object is to provide a mouthpiece in which no metal, with its corroding and tarnish- "ing tendencies, is used in proximity to the lip-porthe glass lip-portion, which of necessity was made relatively heavy.

All these objects and others hereinafter re--' ferred to, are attained by this invention by making the sound collector ormouthpiece relatively large and gradually tapering inwardly, and by using a nitro-cellulose product as the material thereof, which is of such thickness that it will resiliently yield and not break when violently struck against the dictating machine, the desk or the floor. Such material, it has been found, is substantially non-resonant under ordinary conditions, and hence does not appreciably modify the ordinary sound it collects; yet it tends to absorb, because of its yielding nature, some of the harsh and excessively intense sounds, and thus eliminates to a large measure blasting of the diaphragm of the dictating machine to which it is connected.

Preferably the material is treated so as to be relatively hard to ignite and'so as to have a relatively low rate of burning.

As will hereinafter appear, the present invention also provides for securing the nitro-cellulose, sound-collector or mouthpiece to the sound-contive means; This preferably comprises a metallic ferrule (aluminum is satisfactory) secured by rivets to the sound-collector and adjustably attached to a sound-conveyor by a clamping screw.

Other objects and advantages will hereinafter appear.

In the accompanying drawing, which illustrates the present invention in its preferred form- Figure l is a side elevation of the handle of the sound-conveyor or speaking-tube with the mouthpiece of the present invention attached thereto, a portion of the mouthpiece being broken away to show its construction.

Fig. 2 is a transverse section taken on the line 2-2 of Fig. 1, showing the construction of the nitro-cellulose mouthpiece.

Fig. 3 is a longitudinal section through the lower portion of the mouthpiece, its ferrule and the handle portion of the sound-conveyor or speaking-tube to which it is attached.

As shown in the accompanying drawing, the sound-conveyor or speaking-tube 10 is attached to a handle-portion 11 made of metal, preferably aluminum for lightness, and this handle-portion has a finger guard or guide 12 provided thereon at one side and a manually operable stop-andstart button 13 at the other side. The speakingtube leads to the dictating machine where the sound which is conveyed is recorded or reproduced while the handle 11 on the other end of the speaking-tube is connected to the mouthpiece 16 in a manner hereinafter described.

As stated above, the mouthpiece, which for the purpose of the present specification is intended to mean all that portion of the sound-collector up to the handle 11, is made large enough at its lip 14 to collect a major portion of the sound emitted by a speaker or dictator while the lip 14 is held at such a distance from the face of the speaker that the sound emitted both through the throat and through the nose is collected. For practical purposes and by way of example, the internal diameter of the lip-portion 14 is preferably about 2%; inches.

From the lip-portion 14, the mouthpiece gradually tapers through its throat portion 16 where it connects with the handle 11 and has substantially the same internal diameter as the handle 11. As shown, the mouthpiece is bent so that the lip 14 lies in a plane at an angle to the axis of the handle 11, so that the handle 11 may be held in a more convenient position by the operator while the lip 14 is substantially parallel with the dict'ators face. In order that the taper may be sufficiently gradual, it is necessary that the mouth piece be rather long, and hence the mouthpiece is large both in cross-sectional area and in length.

Such a mouthpiece as shown, when made of metal of sufiicient rigidity so that it would not vibrate and thus modify the sound being collected, is excessively heavy and its weight is augmented by the provision of a glass lip engaging portion which of necessity is also heavy. While such a metal and'glass mouthpiece is practicable and has been used to a considerable extent, nevertheless, it has been found fatiguing to dictators to hold this mouthpiece in speaking position for any considerable length of time.

The present invention, therefore, as statedv above, has for its object the provision of an acoustically efiicient mouthpiece which is not excessively heavy. In attaining this end, the present invention has provided a mouthpiece. made of; Intro-cellulose such as pyralin, celluloid or like material which, because of its non-resonant characteristic, may be used much thinner than metal of the same characteristic. Moreover, it has been found that a mouthpiece made of such material,

when made sufficiently thin, tends to absorbinthe walls of it some of the energy of exceptionally loud or harsh sounds and passes these sounds on to the sound-conveyor in a somewhat modified form. Hence, it materially eliminates blasting ofthe diaphragm connected with the sound-conductor. Again, it has been found that a mouthpiece of nitro-cellulose or like material when made Water, and it has none ofthe disadvantages of some metals which, due to the moisture deposited upon them (because the mouthpiece is located directly in front of the speakers mouth) tarnish or corrode.

While light materials of various thickness may be employed, yet it is preferable, as shown by actual experiment, to use material ranging from 5 to. %6 of an inch in thickness. 1

Practical tests have also shown that it ispreferable that the lip 14 or outer portion of the mouthpiece be made about twice as thick as the main body portion 1'7, as shown at 15. Hence, for this reason and for the reason that it is more desirable to make the mouthpiece out of sheet pyralin rather than by other methods, the lip-portion 14 is made separate from the body portion 17 and these two portions are united preferably by a lap joint 18 held together by adhesion.

Y Because it is alsopreferable to make it out of sheet material, the body portion 17 is also made of two parts, 17a and 17b, and these are united by lap joints '19 secured together by adhesion. These lap joints 19 have the further advantage of strengthening the body portion 17 against collapsing and against bending in the direction of the incline of the mouthpiece.

. t its throat end 16, the mouthpiece is preferably riveted or otherwise secured to a metallic ferrule 20, preferably of aluminum, which extends beyond the throat portion 16, so that a part of it can overlie the end of the handle 11 and telescope with it. The mouthpiece and handle when so telescoped are held together by means of a screw 21 passing through a hole 22 in the ferrule and threaded into the handle 11, so that as at 23 to provide a smooth round surface which might be brought into contact with the dictators having a body-portion made of .nitro-cellulose,

when the screw is adjusted in place the mouthpiece and the handle will be held firmly together.

In order to permit the mouthpiece to be adjusted about the axis of the handle so that the inclination of the lip-portion 14 may be varied with regard to the manually operable button 13 and the finger guard 12 on the handle, the hole 22 is elongated so as to form a slot allowing movement of the ferrule and mouthpiece with regard to the screw when the screw is loosened. When the screw is tightened, the head thereof holds the ferrule securely in place against rotary or other movements.

Preferably, the lip-portion 14 is beaded over and a lip-portion made of nitro-cellulose of substantially twice the thickness of the nitro-cellulose of the body-portion and secured to said bodyportion to form therewith a substantially integral structure.

2. A sound-collector for dictating machines having a body portion comprising two parts of sheet nitro-cellulose secured together side-byside to form part of a horn-shaped structure; and a lip-portion of sheet nitro-cellulose secured to. the said two-parts to complete the horn-shaped structure. 7 V

3. A sound-collector for dictating machines having a body portion comprising two parts of'1l5 sheet nitro-cellulose substantially of an inch in thickness, said parts being secured together to form part of a horn-shaped structure; and a lip-' portion of sheet nitro-cellulose of substantially 1%? of an inch in thickness secured to said two parts to complete the horn-shaped structure.

4. A sound-collector for dictating machines having a body portion comprising a plurality of parts of sheet material secured together side by side to form a horn-shaped structure, and a lip portion of substantially twice the thickness of the body portion secured to the said parts to complete the horn-shaped structure.

5. A sound-collector for dictating machines having a body portion comprising a plurality of parts ofsheet nitrocellulosecemented together along their longitudinal edges to form a horn. shaped structure, and a nitrocellulose lip portion of substantially greater thickness than said body portion cemented to said bodyportion along its circumferential overlapping edges.

6. A sound-collector for dictating machines having a body portion comprising a plurality of parts of sheet materialsecured together side by side to form part of a horn shaped structure, said parts being cemented together along overlapping edges to provide ribs extending longitudinally of the horn shaped structure for stiffening purposes, and a nitrocellulose lip portion of substantially greater thickness than said body portion cemented to said body portion along its circumferential overlapping edges.

7. A sound-collector for dictating machines having a body-portion comprising two parts of sheet nitro-cellulose secured together side-byside to form part of a horn-shaped structure, a metallic ferrule riveted to the throat of said bodyportion for connecting it to a sound-conduit, and a lip-portion of sheet nitro-oellulose secured to the other end of said body-portion to complete the horn-shaped structure.

8. A sound-collector for dictating machines having a body-portion comprising two parts of sheet nitro-cellulose secured together side-by-side to form part of a horn-shaped structure, and a lip-portion of sheet nitro-cellulose of greater thickness than the sheet material of the bodyportion and secured to said body-portion to complete the horn-shaped structure.

9. A sound collector for dictating machines having a body portion of nitro-cellulose, a lip portion made of nitro-cellulose having a thickness substantially greater than the thickness of the body portion, said lip portion being secured to said body portion to form therewith a substantially integral structure.

10. A sound collector for dictating machines,

including an elongated body portion formed from 

